ImperialCoins typed:
snip

Replacing salt with what remains after evaporation is a bad idea.
Some salts do not remain stable through the process of evaporation
and a lot is lost in the process. (The main reason why we cant
just evaporate sea water and re-hydrate it for our tanks- it would
not work well at all.)

-Alfred

Not to mention the dust and crud that settles on it. Yuk.